Einleitung

Postoperative adhesions occur in more than 90% of cases following abdominal surgery. They are responsible for chronic pain, reduced quality of life, female secondary infertility and life threatening complication like bowel obstruction. Besides surgical techniques, a variety of chemical agents exist to prevent adhesion formation after operation. Aim of this study was to test the efficacy of a novel agent, 4DryField® PH, for its suggested anti-adhesive properties in a rat model. 4DryField® PH is a novel powder made of high pure plant-based polysaccharides without any animal or human ingredients, which is CE certified for use as hemostat. In addition, 4DryField® PH as a pure modified starch is capable to form a starch gel. Those gels are widely used in several medical applications (acting as barriers, superficially covering wounded areas).

Material und Methoden

For adhesion induction a modified rat model as described by Harris et al. (1995) was used. Adhesions were induced in male Lewis rats by cecal abrasion, creation of an abdominal wall defect and approximation of injured areas by suture. Animals of group 1 received no anti-adhesive agent, whereas to animals of group 2 4DryField® PH was administered as a gel preparation (vol. 1.2ml, conc. 250mg/ml). All rats were sacrificed at day 7. Formation of adhesions was evaluated by macroscopic quantification by two independent observers using scoring systems of Lauder et. al (2011) and by Hoffmann et al. (2009). Samples for histological examinations were excised en bloc. Serial paraffin embedded sections were stained with haematoxylin and eosin respectively Alcian blue and PAS. Results were statistically analyzed using Student’s T-Test.

Ergebnisse

All animals showed equitable viability and course of body weight. In group 1 (n=10), 9 of 10 animals developed adhesions of maximum quantity and quality. 4DryField® PH gel treated animals of group 2 (n=10) revealed a marked reduction of adhesion quality and quantity with respect to all subscores and total scores. According to Lauder et al. animals of group 1 were rated with a score of 4.5 ± 1.6 (maximum score would be 5.0) whereas those of group 2 gained a score of 0.7 ± 1.3. Using the Hoffmann scoring system, total score in group 1 was 9.0 ± 3.2 (maximum score would be 10.0) and in group 2 2.0 ± 3.5. Histopathological evaluation showed in all animals of group 2 starch residues within the abdominal wall defect. Comparing the results after treatment with controls there was a reduction of 89% with respect to observed adhesion formation (p < 0.0001).

Schlussfolgerung

Following surgery involving the peritoneum, adhesions occur in up to more than 90% of cases. In order to evaluate the capability of products to prevent adhesions, an optimized experimental model to provoke adhesions was developed on the basis of Harris et al. (1995) with cecal abrasion and creation of an abdominal wall defect in rats. Our data show that 4DryField® PH was highly effective in preventing adhesion formation in animals of group 2. With the use of 4DryField® PH the prospected rate of high degree adhesions (90% in control group) could be reduced to 10%, which means a reduction rate of 89%. Compared to results described in the literature obtained with other products (Adept®, Interceed®, Seprafilm®) the mean reduction rate was 38%. 4DryField® PH gel applied to significant mesothelial wounds was capable to prevent adhesions between parietal and visceral mesothelium with a reduction rate of 89% without any detectable adverse events.